What Is Google Webmaster Tools?

Webmaster Tools is a free program by Google which helps the average online user understand various aspects about the structure of their website and any issues that are arising due to complications or errors with navigation and content. It shows:

How visitors came to find the site

Issues with plugins, content, applications or media

More detailed analytics

If the website has been penalised

It can be very helpful as it identifies and informs you of when your website may be down or failing to function properly or at its best from an analytics perspective.